
Using the Eigensystem Realization Algorithm (ERA) detailed in Ref. [1]}, the convolution integral can be expressed in terms of the realized state-space matrices \(\textbf {A}_r, \textbf {B}_r\)  and \(\textbf {C}_r\)  as:
\( h(t)=\left(M \sqrt{\frac{g}{R}} \right)\textbf {C}_r e^{\textbf {A}_rt} \textbf {B}_r,\) 
